Least k > 1 such that S000980(n) divides k^k + (-1)^k (k-1)^(k-1).
257, 130, 1430, 10702, 16252, 38398, 52171, 11277, 43792, 8979, 139405, 81502, 9947, 47125, 182786, 115331, 11858, 323058, 176506, 86557, 178860, 118574, 59710, 372441, 38138, 194807, 223738, 27636, 450455, 185831, 36759, 725266, 705064, 189861, 651247
1
The variability of this function makes the completeness of A238194 an issue.
T. D. Noe, Plot of 153 terms
T. D. Noe, Table of 153 terms
David W. Boyd, Greg Martin, and Mark Thom, Squarefree values of trinomial discriminants, LMS J. Comput. Math. 18 (1) (2015), p. 148-169
(Mma) t2 = {}; Do[s = Select[Range[2, p^2], Mod[PowerMod[#, #, p^2] + (-1)^# PowerMod[# - 1, # - 1, p^2], p^2] == 0 &, 1]; If[Length[s] > 0, AppendTo[t2, s[[1]]]], {p, Prime[Range[PrimePi[1000]]]}]; t2
nonn,hard
T. D. Noe, Mar 18 2017